Conventional blades of electrophotographic apparatus (hereinafter simply referred to as blades) have been made of resin materials to which a metallic plate is adhered for carrying out static charge control of a toner, thinning of a toner layer electrostatically adsorbed to a toner-feeding roller, and removal of the toner remaining on a photoreceptor after toner transfer by scraping to clean the photoreceptor in the development zone of a dry process electrostatic copying machine.
The resin materials which have been generally used in such blades for electrophotographic apparatus (hereinafter simply referred to as blades) include urethane rubbers and silicone rubbers.
The blade is generally composed of resin blade 22 of a plate shape which is adhered to metallic holder 21 of a plate shape on surface of adhesion 23 as shown in FIG. 20. The conventional blade of this type has been manufactured by adhering resin plate 22 to metallic holder 21 and post-finishing the portion of the resin plate 22 to be in contact with a development roller or a photoreceptor by cutting or polishing.
The materials to be used for the blades of electrophotographic apparatus are required to have properties of repelling an object in contact, such as a toner, or allowing no penetration of such an object, as well as charging characteristics. It is also demanded that they can be manufactured through processes requiring no post-finishing, etc.
However, urethane rubbers which have been used in the conventional blades of electrophotographic apparatus have problems in charging characteristics and toner adhesion. Silicone rubbers also have problems in charging characteristics. Compounding of a charge depressant as disclosed in JP-A-No. 61-173270 sometimes brings about slight improvements, but compounding of a charge depressant gives rise to another problem that the blade itself becomes brittle. In addition, since the silicone rubbers are heat-curable resin having a crosslinking structure, they essentially require post-finishing.
Post-finishing including cutting is carried out for obtaining dimensional precision of the tip of the blade. Because the dimensional precision of the blade tip has influences on the state of a thin toner layer and the like, namely great influences on image quality, the post-finishing for obtaining a blade of desired dimensional precision entails much labor with inefficiency and bad economy.